Camera module and manufacturing method thereof

ABSTRACT

A camera module includes a lens unit containing a lens, a holding member provided with an image sensor and an engaging member of cured resin. At least a part of the engaging member includes a surface that intersects with a direction of an optical axis of the lens and the lens unit and the holding member are engaged with each other on the surface.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority from and the benefit of JapanesePatent Application No. 2015-212391 filed on Oct. 28, 2015, the entirecontents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a camera module and a manufacturingmethod thereof.

BACKGROUND

In a camera module, a lens unit having a lens and a holding memberhaving an image sensor are fixed with screws after the lens and theimage sensor are aligned with each other. In this case, when screws aretightened, an external force caused by rotation of screws or sinking ofthe member is applied to the lens unit or the holding member, andaccuracy of alignment between the lens and the image sensor may bereduced. To prevent this, there is a method of fixing a lens unit and aholding member with an adhesive (see, for example, the patent literature1 (PTL 1)). An interfacial failure can often occur at an interfacebetween the adhesive and a member to be adhered.

CITATION LIST Patent Literature

PTL 1: JP2014-186212 A

SUMMARY

A camera module according to an embodiment of this disclosure includes alens unit having a lens, a holding member provided with an image sensorand an engaging member of cured resin. At least a part of the engagingmember includes a surface that intersects with the direction of anoptical axis of the lens. The engaging member engages the lens unit andthe holding member with each other on the surface.

A manufacturing method of the camera module according to an embodimentof this disclosure includes a step of filling a resin with a lens unithaving a lens and a holding member provided with an image sensor alignedwith each other in the direction of the optical axis of the lens. Themanufacturing method includes a step of curing the resin to produce anengaging member of cured resin that engages the lens unit and theholding member with each other. At least a part of the engaging memberincludes a surface that intersects with the direction of the opticalaxis of the lens. The engaging member engages the lens unit and theholding member with each other on the surface.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1 is an exploded perspective view illustrating a configurationexample of a camera module according to Embodiment 1;

FIG. 2 is a perspective view of a lens unit in FIG. 1 seen from an imagesensor side;

FIG. 3 is a cross-sectional view of the camera module in FIG. 1;

FIG. 4 is an enlarged view of a boss and its periphery;

FIG. 5 is a flowchart illustrating an example of a manufacturing methodof the camera module;

FIG. 6 is a perspective view of a configuration example of a lens unitaccording to Embodiment 2 seen from an image sensor side;

FIG. 7 is a cross-sectional view of a camera module in FIG. 6;

FIG. 8A is a perspective view of a configuration example of a lens unitaccording to Embodiment 3 seen from an image sensor side;

FIG. 8B is a perspective view of a configuration example of the lensunit according to Embodiment 3 seen from the image sensor side;

FIG. 9 is an enlarged cross-sectional view of a hole provided in thelens unit in FIG. 8A;

FIG. 10A is an enlarged cross-sectional view of a rib and a grooveprovided in a lens unit according to an comparative example ofEmbodiment 4;

FIG. 10B is an enlarged cross-sectional view of the rib and the grooveprovided in the lens unit according to Embodiment 4;

FIG. 11A is a cross-sectional view illustrating an example of a holeprovided in a lens unit according to Embodiment 5;

FIG. 11B is a cross-sectional view illustrating an example of the holeprovided in the lens unit according to Embodiment 5;

FIG. 12A is a cross-sectional view illustrating an example of a bossprovided in a lens unit according to Embodiment 6;

FIG. 12B is a cross-sectional view illustrating an example of the bossprovided in the lens unit according to Embodiment 6;

FIG. 13 is an exploded perspective view illustrating a configurationexample of a camera module according to Embodiment 7;

FIG. 14 is an enlarged cross-sectional view of a portion into which aspacer is inserted in FIG. 13;

FIG. 15 is a plan view (upper half) and a side view (lower half) of thespacer in FIG. 13;

FIG. 16 is a flowchart of a manufacturing method of the camera module inFIG. 13;

FIG. 17 is a diagram illustrating a positional relationship between animaging area and an extraction area;

FIG. 18 is a diagram illustrating a configuration example of fillingholes provided with notches according to Embodiment 9;

FIG. 19 is a diagram illustrating a configuration example of a bossprovided with a notch according to Embodiment 9; and

FIG. 20 is a cross-sectional view taken from line A-A in FIG. 19.

DETAILED DESCRIPTION Embodiment 1

Schematic figures are used in the following description. These figuresare not necessarily to scale.

[Camera Module Configuration]

As illustrated in FIG. 1, a camera module 1 includes a lens unit 2 and aholding member 3. The lens unit 2 has a lens 21. The lens 21 is fixed tothe lens unit 2. The holding member 3 has an image sensor 31. The imagesensor 31 is fixed to the holding member 3. The holding member 3 isprovided with a filling hole 32. The holding member 3 may be providedwith a plurality of filling holes 32. In FIG. 1, three filling holes 32are provided. The lens unit 2 and the holding member 3 can be fixed atthree positions by three filling holes 32. The number of the fillingholes 32 is not limited to three.

The lens unit 2 and the holding member 3 are engaged with each other byfilling an adhesive from the filling holes 32 with the lens 21 and theimage sensor 31 aligned with each other and by curing the adhesive. Theadhesive may be a resin such as epoxy, but is not limited thereto. Theadhesive may be a photo-curable resin that cures when irradiated with alight. The light may be a UV light, for example, but is not limitedthereto. The adhesive may be a thermosetting resin that cures whenapplied with heat. The adhesive may be other cured resins. In thisapplication, “engagement” means that two or more members are engagedwith each other to be integrated such that their movements are regulatedwith each other.

The state where the lens 21 and the image sensor 31 are aligned witheach other means that they are aligned with respect to the direction ofan optical axis 5 of the lens 21 and with respect to the directionperpendicular to the optical axis 5, respectively. The direction of theoptical axis 5 of the lens 21 is also referred to as an axial direction.The direction perpendicular to the optical axis 5 of the lens 21 is alsoreferred to as a radial direction. The state where they are aligned withrespect to the radial direction is a state where the optical axis 5 ofthe lens 21 coincides with a perpendicular line passing through thecenter of a light receiving surface of the image sensor 31. The statewhere they are aligned with respect to the axial direction means that astate where the image forming position of the lens 21 coincides with thelight receiving surface of the image sensor 31. When the distance fromthe camera module 1 to an object is far enough to be regarded asinfinity, the image forming position of the lens 21 coincides with theposition that is far away from the lens 21 by its focal length.

As illustrated in FIG. 2, the lens unit 2 has an opening 20, bosses 22and holes 23. The opening 20 is a portion through which a light incidenton the lens 21 passes and reaches the image sensor 31. At the opening20, an optical material such as one or more other lenses or variousfilters that form the optical system are disposed with the lens 21.Three bosses 22 and holes 23 are provided relative to each position ofthe filling holes 32 of the holding member 3. Each boss 22 projects atleast partially along the direction of the optical axis 5 as illustratedin FIG. 1. Each hole 23 extends at least partially along the directionof the optical axis 5.

As illustrated in FIG. 3, the camera module 1 further includes anengaging member 4 formed by curing an adhesive. The engaging member 4formed by curing an adhesive is also referred to as an engaging member 4of a cured resin. At least a part of the engaging member 4 includes asurface that intersects with the direction of the optical axis 5 of thelens 21. The engaging member 4 engages the lens unit 2 and the holdingmember 3 with each other on the surface that intersects with thedirection of the optical axis 5 of the lens 21. Each boss 22 of the lensunit 2 is provided such that it projects to the side facing the holdingmember 3. Each boss 22 and each hole 23 of the lens unit 2 may have anaxis in approximately the same direction with that of the optical axis 5of the lens 21, but not limited thereto.

Each boss 22 has a surface on the side facing the holding member 3. Anadhesive is filled in a space between the surface of the boss 22 on theside facing the holding member 3 and the holding member 3, and into thehole 23. The filled adhesive cures and is formed as an engaging member4. In other words, the engaging member 4 is produced by curing thefilled adhesive. The surface of the boss 22 facing the holding member 3is in contact with the engaging member 4.

As illustrated in FIG. 4, the engaging member 4 formed by curing theadhesive spreads between the lens unit 2 and the holding member 3, intothe hole 23 of the lens unit 2, into the filling hole 32 of the holdingmember 3 and over the first surface of the holding member 3. The firstsurface of the holding member 3 is a surface opposite the surface facingthe lens unit 2. The space between the lens unit 2 and the holdingmember 3 is narrowed by projecting the boss 22 from the lens unit 2.When the boss 22 is provided, the amount of adhesive filled between thelens unit 2 and the holding member 3 can be decreased.

In FIG. 4, the engaging member 4 includes a first part present on afirst surface of the holding member 3 and a second part present betweenthe lens unit 2 and the holding member 3. The end of the filling hole 32of the holding member 3 is sandwiched by the first part and the secondpart of the engaging member 4 in the direction of the optical axis 5.The end of the filling hole 32 is at least a part of the holding member3. In another aspect, a normal line directing from the lens unit 2 tothe engaging member 4 on at least a part of the surface of the engagingmember 4 in contact with the holding member 3 is a component of thedirection directing to the side of the lens unit 2 and has a componentthat is parallel to the optical axis 5 of the lens 21. Suchconfiguration prevents the holding member 3 and the engaging member 4from moving each other to the direction of the optical axis 5.

Further, in FIG. 4, the hole 23 provided in the lens unit 2 has internalthreads. These internal threads are sandwiched in the direction of theoptical axis 5 by the engaging member 4 present in the hole 23 such thatthe movement in the direction of the optical axis 5 is prevented. Atleast a part of the lens unit 2 or at least a part of an innerperipheral surface of the hole 23 of the lens unit 2 is sandwiched bythe engaging member 4 in the direction of the optical axis 5. In anotheraspect, a normal line directing from the lens unit 2 to the engagingmember 4 on at least a part of the surface of the engaging member 4 incontact with the lens unit 2 has a component of the direction that is inparallel with the optical axis 5 and is toward the side of the holdingmember 3. Besides the adhesive force of the engaging member 4, suchconfiguration prevents the lens unit 2 and the engaging member 4 frommoving each other toward the optical axis 5. Instead of provided withinternal threads, the hole 23 may be subjected to emboss processing.Even when the hole 23 is subjected to emboss processing, the lens unit 2and the engaging member 4 are prevented from moving each other towardthe optical axis 5. When the hole 23 is provided with internal threads,it is considered that the engaging member 4 filled in the hole 23 andcured therein has a form of resin screw in the hole 23.

The lens unit 2 and the holding member 3 are engaged respectively withthe engaging member 4, and thus are prevented from moving each othertoward the optical axis 5, that is, prevented from moving in the axialdirection. As a result of this, the distance between the lens 21 and theimage sensor 31 is maintained, and the state where they are aligned witheach other in the axial direction is maintained. When the lens unit 2and the holding member 3 move each other in the axial direction, acompression force or a tensile force is applied to the engaging member4.

The lens unit 2 and the holding member 3 are prevented respectively frommoving in the direction perpendicular to the optical axis 5, that is, inthe radial direction, due to a presence of the engaging member 4 in thehole 23 and the filling hole 32. As a result of this, the state wherethe optical axis 5 of the lens 21 and the perpendicular line passingthrough the center of the light receiving surface of the image sensor 31coincident with each other is maintained, and the state where they arealigned with each other in the radial direction is maintained. When thelens unit 2 and the holding member 3 intend to move each other in theradial direction, a shear force is applied to the engaging member 4.

When representing the configuration of the lens unit 2 and the holdingmember 3 engaged with each other in another aspect, the lens unit 2 andthe holding member 3 are provided respectively with a first engagingpart and a second engaging part. The engaging member 4 connects thefirst engaging part and the second engaging part in the direction of theoptical axis 5. The first engaging part corresponds to the hole 23provided in the lens unit 2. The second engaging part corresponds to thefilling hole 32 provided in the holding member 3.

The first engaging part corresponding to the hole 23 is aregulation-shaped hole that regulates the lens unit 2 and the engagingmember 4 from moving each other toward the optical axis 5. The secondengaging part corresponding to the filling hole 32 is a through holepassing through the holding member 3.

In other words, the hole corresponding to the first engaging part andthe through hole corresponding to the second engaging part arecommunicated by the engaging member 4, and the engaging member 4 isrestricted from moving toward the optical axis 5 by the regulation shapeof the hole.

The engaging member 4 may maintain the engagement between the lens unit2 and the holding member 3 not by means of an adhesive force of theinterface with them, but by means of a tensile force, a compressionforce or a shear force applied to the engaging member 4 itself. When thestrength of the cured adhesive itself that forms the engaging member 4is larger than the adhesive force of the interface, the configurationillustrated in FIG. 4 indicates an engaging force that is larger thanmere adhesion.

Thus the lens unit 2 and the holding member 3 can be fixed withoutapplying an external force after alignment. Positional misalignmentbetween the lens unit 2 and the holding member 3 when fixing them can beprevented.

Members such as screw and vis are not needed. Omitting a space formembers such as screw and vis allows for a design with a high degree offreedom.

[Camera Module Manufacturing Method]

The manufacturing method of the camera module 1 is performed followingthe flowchart illustrated in FIG. 5. The lens unit 2 and the holdingmember 3 are aligned with each other in the radial direction (step S2).As illustrated in FIG. 1, the lens unit 2 and the holding member 3 maybe moved respectively such that the optical axis 5 of the lens 21coincides with the perpendicular line passing through the center of thelight receiving surface of the image sensor 31.

The lens unit 2 and the holding member 3 are aligned with each other inthe axial direction (step S4). The distance between the lens 21 and theimage sensor 31 is determined such that the image forming position ofthe lens 21 coincides with the light receiving surface of the imagesensor 31. The lens unit 2 and the holding member 3 may be movedrespectively to adjust the distance between the lens 21 and the imagesensor 31.

Alignment between the lens unit 2 and the holding member 3 in steps S2and S4 may be performed with only one of them moved and the other fixedor with both of them moved. Steps S2 and S4 may be reversed. Steps S2and S4 may be performed with lens unit 2 and/or holding member 3 movedby a 6-axis adjustable apparatus, for example. The 6-axis adjustableapparatus may be a robot, for example.

The lens unit 2 and the holding member 3 are temporary held (step S6).The temporal holding may be performed to hold the lens unit 2 and theholding member 3 while they are aligned. The temporal holding may beperformed successively by an apparatus used for alignment, for example,or by mounting a jig for temporal holding.

An adhesive is filled from the three filling holes 32 provided in theholding member 3 (step S8). The adhesive is filled between the boss 22and the holding member 3 and into the hole 23. The adhesive may befilled in the filling hole 32. As illustrated in FIG. 4, the adhesivemay be heaped on the first surface of the holding member 3. When theadhesive is filled in this manner, the lens unit 2 or the holding member3 is not needed to be moved for applying the adhesive. The adhesive canbe filled with the lens unit 2 and the holding member 3 aligned witheach other. The lens unit 2 and the holding member 3 can be connectedwith each other with the holding member 3 aligned with the lens unit 2in the direction of the optical axis 5 of the lens 21.

The adhesive is cured (step S10). As the adhesive, ultraviolet cureadhesive or thermosetting adhesive or the like may be used. Theultraviolet is also referred to as UV (Ultra Violet). The filledadhesive can be cured by UV irradiation on the adhesive or heating ofthe adhesive, or the like. When the adhesive is cured, the lens unit 2and the holding member 3 can be fixed without being applied with anexternal force. Positional misalignment between the lens unit 2 and theholding member 3 cannot be caused by an external force. In thisembodiment, UV curing+thermosetting adhesive, which is a curing by bothUV irradiation and heating, is used. The UV curing+thermosettingadhesive is temporary cured by UV irradiation, and after that, is fullycured by heating, thus can have a larger shear strength. The shearstrength of the adhesive fully cured by heating can increase. When UVcuring+thermosetting adhesive is used, the adhesive is temporary curedby UV irradiation in step S10.

Temporal holding for the lens unit 2 and the holding member 3 is removed(step S12). When the temporal holding is performed by an apparatus usedfor alignment, the temporal holding is removed by removing it from theapparatus. When a jig for temporal holding is mounted, the temporalholding is removed by removing the jig.

The adhesive is fully cured (step S14). The lens unit 2 and the holdingmember 3 are engaged with each other by fully curing the adhesive. Inthis embodiment, the adhesive is fully cured by heating. The temperatureat which the adhesive is fully cured may be lower than the melting pointof each member contained in the lens unit 2 and the holding member 3.

According to the manufacturing method illustrated in FIG. 5, the lensunit 2 and the holding member 3 can be fixed with aligned with eachother without receiving an external force. The lens unit 2 and theholding member 3 do not receive an external force when they are fixed,and thus positional misalignment between them can be prevented. Anadhesive can be filled with the lens unit 2 and the holding member 3aligned with each other. An adhesive can be filled without any of thelens unit 2 or the holding member 3 evacuated. Thus the man-hour forfilling an adhesive can be reduced.

In this embodiment, a temporal curing step by UV irradiation and a fullcuring step by heating are performed as a separate step. The curing stepof adhesive is not limited thereto. For example, both temporal curingand full curing may be performed in step S10.

Embodiment 2

The lens unit 2 may further have a rib 24 that connects three bosses 22.

The lens unit 2 illustrated in FIG. 6 has the rib 24 that connects threebosses 22. The rib 24 may have a groove 25. The groove 25 may connectthe holes 23 provided in the bosses 22. The rib 24 and the groove 25 maybe provided on at least a part of the circumference of the optical axis5. The rib 24 and the groove 25 may be provided over the entirecircumference of the optical axis 5.

The camera module 1 illustrated in FIG. 7 is different from the cameramodule 1 illustrated in FIG. 3 in that the lens unit 2 has the rib 24and the groove 25. The adhesive is filled from the filling hole 32 thatcorresponds to the boss 22 and spreads from the hole 23 to the rib 24and the groove 25. The filled adhesive cures and forms the engagingmember 4. The engaging member 4 may be formed on at least a part of thecircumference of the optical axis 5. The engaging member 4 may beprovided over the entire circumference of the optical axis 5. When theengaging member 4 is formed on all around the optical axis 5, the imagesensor 31 is sealed by the engaging member 4 that extends over the rib24 and the groove 25.

According to the lens unit 2 of this embodiment, the image sensor 31 canbe sealed by the engaging member 4. The adhesive can spread to the rib24 and the groove 25 by a capillary action. The adhesive can be filledin a portion provided with no filling hole 32 with the lens unit 2 andthe holding member 3 aligned with each other. The lens unit 2 or theholding member 3 is not needed to be evacuated when an adhesive isfilled.

Embodiment 3

The lens unit 2 may not have the boss 22.

The lens unit 2 illustrated in FIG. 8A does not have the bosses 22 andhas only holes 23. Besides the configuration illustrated in FIG. 8A, thelens unit 2 illustrated in FIG. 8B further has a groove 25 that connectsthe holes 23.

The lens unit 2 illustrated in FIG. 9 is different from the lens unit 2illustrated in FIG. 4 in that it does not have the boss 22. The adhesiveis filled from the filling hole 32 that corresponds to the hole 23 intothe hole 23. When compared with FIG. 4, the lens unit 2 illustrated inFIG. 9 has a larger space between it and the holding member 3 for nothaving the boss 22. Thus, when the lens unit 2 and the holding member 3are aligned with each other, a movable range in the direction of theoptical axis 5 can be increased.

Embodiment 4

The cross-sectional shape of the groove 25 provided in the lens unit 2may be changed.

The groove 25 provided in the lens unit 2 in FIG. 10A has astraight-shaped cross section in which an opening width is the same asthe bottom width. The groove 25 provided in the lens unit 2 in FIG. 10Bhas a reverse tapered cross section in which the bottom width is largerthan the opening width.

A drag that prevents the engaging member 4 and the lens unit 2 frommoving toward mutually separating direction is generated on the reversetapered part of the groove 25 illustrated in FIG. 10B. When comparedwith the groove 25 illustrated in FIG. 10A, the lens unit 2 having thegroove 25 illustrated in FIG. 10B can be engaged with the engagingmember 4 with a larger engagement strength.

Embodiment 5

The hole 23 provided in the lens unit 2 may be changed into other shapesinstead of being provided with internal threads.

The hole 23 provided in the lens unit 2 in FIG. 11A has a reversetapered cross section in which an interior portion is wider than theopening of the hole 23. As illustrated in FIG. 11B, the hole 23 may havea T-shaped cross section in which an opening of the hole 23 is narrowand the inside thereof extends into a flange shape. In both ofconfigurations illustrated respectively in FIGS. 11A and 11B, the lensunit 2 is prevented from moving to the axial direction of the hole 23 bythe engaging member 4 that is formed by filling an adhesive into thehole 23 and curing the adhesive. In other words, the lens unit 2 isprevented from moving to the direction approximately identical to theoptical direction of the lens 21. Thus the engagement strength betweenthe engaging member 4 and the lens unit 2 can be increased. When thehole 23 has a reverse tapered shape or a T-shaped cross section, theengaging member 4 filled in the hole 23 and cured may take a form ofresin rivet in the hole 23.

Embodiment 6

The lens unit 2 may be provided with a projection 26.

The lens unit 2 illustrated in FIG. 12A is provided with the projection26. The projection 26 has a constriction 26 a. The projection 26 has aT-shaped cross section. As illustrated in FIG. 12B, the lens unit 2 andthe holding member 3 may be engaged with each other by the engagingmember 4 formed by curing the adhesive filled in the constriction 26 bof the projection 26 illustrated in FIG. 12A. In the configurationillustrated in FIG. 12B, the projection 26 is prevented from moving inthe axial direction, that is, the direction approximately identical tothe optical direction of the lens 21, by the engaging member 4. Thus,the engagement strength between the engaging member 4 and the lens unit2 can be increased.

In FIGS. 12A and 12B, the lens unit 2 is engaged with the engagingmember 4 by the shape feature of the boss 22, and then is engaged withthe holding member 3. In FIGS. 12A and 12B, the lens unit 2 may beprovided with the hole 23. When the hole 23 is provided, the engagementstrength between the engaging member 4 and the lens unit 2 can befurther increased.

Embodiment 7

Alignment between the lens unit 2 and the holding member 3 in the axialdirection may be performed by using a spacer 41.

The camera module 1 illustrated in FIG. 13 includes the lens unit 2 andthe holding member 3. The lens unit 2 is provided with the opening 20,the bosses 22 and the holes 23. The holding member 3 is provided withfilling holes 32 used for filling an adhesive. The bosses 22 and theholes 23 are provided relative to the filling holes 32, respectively. Aposition corresponding to the filling holes 32 located between the lensunit 2 and the holding member 3 is provided with a spacer 41 serving asa distance adjusting member. The spacer 41 may be an annular member suchas a washer, for example, but is not limited thereto.

The camera module 1 illustrated in FIG. 13 may be assembled in thefollowing procedures. The lens unit 2 and the holding member 3 arealigned with each other in the radial direction such that the opticalaxis 5 of the lens 21 coincides with the perpendicular line passingthrough the center of the light receiving surface of the image sensor31.

The spacer 41 is inserted between the lens unit 2 and the holding member3. The lens unit 2 and the holding member 3 are aligned in the axialdirection such that they abut the spacer 41 respectively. When they arealigned with each other in the axial direction, the distance between thelens 21 and the image sensor 31 is determined depending on the thicknessof the spacer 41. The thickness of the spacer 41 may be determined inadvance such that the image forming position of the lens 21 of the lensunit 2 coincides with the light receiving surface of the image sensor 31of the holding member 3. The distance between the lens 21 and the imagesensor 31 may be measured with the spacer 41 having a differentthickness abutted the lens unit 2 and the holding member 3. Thethickness of the spacer 41 may be determined on the basis of the actualmeasurement of the distance between the lens 21 and the image sensor 31.A chart or the like that evaluates the state of focus of a capturedimage may be captured with the spacer 41 inserted. The thickness of thespacer 41 may be determined on the basis of the evaluation results ofthe chart or the like. A plurality of spacers 41 may be inserted. Thelens unit 2 and the holding member 3 can be aligned with each other bythe combined thickness of a plurality of spacers 41.

After the lens unit 2 and the holding member 3 are aligned with eachother such that the lens 21 and the image sensor 31 are aligned witheach other, an adhesive is filled from the filling hole 32. The lensunit 2 and the holding member 3 are engaged with each other by curingthe adhesive.

In FIG. 13, the engaging member 4 formed in advance is indicated at aposition corresponding to the filling hole 32. FIG. 13 is illustrated asan exploded perspective view. FIG. 13 does not illustrate that theengaging member 4 formed by curing the resin is mounted when the cameramodule 1 is assembled. The engaging member 4 is formed by curing theadhesive filled from the filling hole 32 after the lens unit 2, theholding member 3 and the spacer 41 are aligned with each other.

As illustrated in FIG. 14, the lens unit 2 and the holding member 3 mayabut respectively the spacer 41.

In this embodiment, the alignment between the lens unit 2 and theholding member 3 in the axial direction is performed by abutting thelens unit 2 and the holding member 3 against the spacer 41. Thus adevice used for assembly does not require to be aligned in the axialdirection. A device used for assembly may have less number of movableshafts.

As illustrated in FIG. 15, the spacer 41 may include a spacer hole 42and a spacer groove 43. The spacer 41 illustrated in FIG. 15 is usedsuch a manner that the surface illustrated as a plan view faces the lensunit 2 or the holding member 3.

The spacer hole 42 is a through hole that extends in the direction ofthe optical axis 5 in the camera module 1. When the camera module 1 isassembled, the adhesive may be filled such that it passes through thespacer hole 42 into the boss 22 or the hole 23 of the lens unit 2.

The spacer groove 43 may be provided in the surface of the spacer 41that faces the lens unit 2 or the holding member 3. When the spacergroove 43 is provided in the surface that faces the holding member 3,the adhesive can easily reach the inside of the surface that abuts theholding member 3 and the spacer 41. The spacer groove 43 may be usedsuch that it aligns with the groove 25 of the lens unit 2 illustrated inFIG. 7 or FIG. 8B. When the spacer groove 43 is aligned with the groove25, an adhesive can be filled successively from the spacer groove 43 tothe groove 25. This configuration allows for stronger engagement betweenthe holding member 3 and the spacer 41.

The manufacturing method of the camera module 1 according to thisembodiment can be performed along the flowchart illustrated in FIG. 16.Measurement for aligning the lens unit 2 and the holding member 3 witheach other in the radial direction is performed (step S22). At least oneof the lens unit 2 and the holding member 3 may be moved such that, asillustrated in FIG. 1, the optical axis 5 of the lens 21 coincides withthe perpendicular line passing through the center of the light receivingsurface of the image sensor 31. The position of the lens unit 2 and theposition of the holding member 3 may be measured respectively.

In the measurement in step S22, only one of the lens unit 2 and theholding member 3 may be moved and the other may be fixed. Both of thelens unit 2 and the holding member 3 may be moved. The lens unit 2and/or the holding member 3 may be moved by a 4-axis adjustable device,for example. The 4-axial adjustable device may be a robot, for example.

Measurement for aligning the lens unit 2 and the holding member 3 witheach other in the axial direction is performed (step S24). The distancebetween the lens 21 and the image sensor 31 may be determined such thatthe image forming position of the lens 21 coincides with the lightreceiving surface of the image sensor 31. When the distance between thelens 21 and the image sensor 31 is determined, the positionalrelationship between the lens unit 2 and the holding member 3 isdetermined. In step S24, measurement for determining the distancebetween the lens 21 and the image sensor 31 is performed such that theimage forming position of the lens 21 coincides with the light receivingsurface of the image sensor 31.

One of the method of determining the distance between the lens 21 andthe image sensor 31 is inserting a spacer 41 having various thicknessesdifferent from each other between the lens unit 2 and the holding member3 and actually measuring the distance between the lens 21 and the imagesensor 31. Other methods include taking an image of a chart or the likewith the spacer 41 inserted to evaluate the focus state of a capturedimage.

Step S22 and step S24 may be reversed.

Measurement for alignment in the axial direction in step S24 can beomitted by using the lens focus data or the height measurement data ofthe image sensor 31.

When the alignment in the radial direction is omitted by making anadjustment through extraction from an image captured by the image sensor31, the measurement for alignment in the radial direction in step S22can be omitted. Even when the lens 21 and the image sensor 31 aremisaligned with each other in the radial direction, an image equivalentto that in the case where an alignment in the radial direction isperformed can be obtained by setting an extraction area 61 in the rangeof the capturing area 60 as illustrated in FIG. 17.

An optimum thickness value of the spacer 41 is determined on the basisof the results of the measurement in step S24 (step S26).

The spacer 41 having a thickness determined in step S26 is mountedbetween the lens unit 2 and the holding member 3 (step S28). Thepositional relationship between the lens unit 2 and the holding member 3in the axial direction is regulated by the spacer 41. The positionalrelationship between the lens unit 2 and the holding member 3 in theradial direction can be adjusted on the basis of the results of themeasurement made in step S22. The adjustment of the positionalrelationship between the lens unit 2 and the holding member 3 in theradial direction may be performed by moving the lens unit 2 and/or theholding member 3 using a 4-axis adjustable device, for example. The4-axis adjustable device may be a robot, for example.

The lens unit 2 and the holding member 3 are temporary held (step S30).The step S30 is similar to the processing in step S6 as illustrated inFIG. 5. The adhesive filling step (step S32), the adhesive temporalcuring step (step S34), the temporal holding removal step (step S36) andthe adhesive full curing step (step S38) are respectively the same asstep S8, S10, S12 and S14 in FIG. 6.

Embodiment 8

In this embodiment, the rib 24 and the groove 25 are provided to connectthe bosses 22 and the holes 23. Further, in variant 2, the groove 25 isprovided to connect the holes 23. The lens unit 2 may not be providedwith the bosses 22, and may be provided with the rib 24 and the groove25 that are provided at least on a part of the circumference of theoptical axis 5. In the lens unit 2, the rib 24 and the groove 25 may beprovided over the entire circumference of the optical axis 5. The lensunit 2 may not be provided with the rib 24, and may include the groove25 provided at least on a part of the circumference of the optical axis5. When the lens unit 2 has the reverse tapered groove 25 as illustratedin FIG. 10B, the lens unit 2 may not include the holes 23. Thus the lensunit 2 may have more simplified configuration.

Embodiment 9

The filling hole 32 of the holding member 3 may have a notch 33 asillustrated in FIG. 18. The filling hole 32 communicates with the end ofthe holding member 3 by the notch 33. When the adhesive filled in thefilling hole 32 is irradiated with UV light, the UV light irradiatedfrom the side of the notch 33 can be irradiated into the filling hole32. The notch 33 provided in the filling hole 32 may increase the degreeof freedom of UV light in the irradiating direction when the adhesive istemporary cured.

The boss 22 having the hole 23 may have a notch 33 as illustrated inFIGS. 19 and 20. The notch 33 allows the hole 23 to communicate with theouter periphery of the boss 22. When the adhesive filled in the hole 23is irradiated with UV light, the UV light irradiated from the side ofthe notch 33 can be irradiated to inside of the hole 23. The notch 33provided in the boss 22 can increase the degree of freedom of the UVlight in the irradiation direction when the adhesive is temporary cured.

REFERENCE SIGNS LIST

-   -   1 Camera module    -   2 Lens unit    -   20 Opening    -   21 Lens    -   22 Boss    -   23 Hole    -   24 Rib    -   25 Groove    -   3 Holding member    -   31 Image sensor    -   32 Filling hole    -   33 Notch    -   4 Engaging member    -   41 Spacer    -   42 Spacer hole    -   43 Spacer groove    -   5 Optical axis

1. A camera module comprising a lens unit containing a lens, a holdingmember provided with an image sensor and an engaging member of curedresin, wherein at least a part of the engaging member includes a surfacethat intersects with a direction of an optical axis of the lens, and onthe surface, the lens unit and the holding member are engaged with eachother.
 2. The camera module according to claim 1, wherein the lens unitis provided with a first engaging part and the holding member isprovided with a second engaging part, and the engaging member engagesthe first engaging part and second engaging part with each other in thedirection of the optical axis of the lens.
 3. The camera moduleaccording to claim 2, wherein the second engaging part is a throughhole, the first engaging part is a hole, the engaging membercommunicates the through hole with the hole, and at least a part of aninner peripheral surface of the hole has a shape that can be sandwichedby the engaging member in the direction of the optical axis of the lens.4. The camera module according to claim 3, wherein the lens unitincludes a plurality of the holes, and further includes a groove thatconnects the holes, and wherein the groove is provided at least on apart of a circumference of the optical axis of the lens.
 5. The cameramodule according to claim 3, wherein the holding member has a notch thatcommunicates an end of the holding member with the through hole.
 6. Thecamera module according to claim 1, wherein the lens unit includes aboss that projects to a side that faces the holding member, and at leasta part of the boss is in contact with the engaging member.
 7. The cameramodule according to claim 6, wherein the lens unit includes a pluralityof the bosses, and further includes a rib that connects the bosses, andwherein the rib is provided at least on a part of the circumference ofthe optical axis of the lens.
 8. The camera module according to claim 1,wherein a normal line on at least a part of a surface of the engagingmember in contact with the holding member has a component that directstoward a side of the lens unit and is in parallel with the optical axisof the lens.
 9. The camera module according to claim 1, furthercomprising a spacer between the lens unit and the holding member. 10.The camera module according to claim 1, wherein the engaging member is aresin rivet.
 11. The camera module according to claim 1, wherein theengaging member is a resin screw.
 12. The camera module according toclaim 1, wherein the cured resin is a photo-curable resin.
 13. Thecamera module according to claim 1, wherein the cured resin is athermosetting resin.
 14. The camera module according to claim 13,wherein the thermosetting resin cures at temperatures lower than amelting point of the lens unit and of the holding member.
 15. A cameramodule manufacturing method comprising steps of: filling a resin with alens unit containing a lens and a holding member provided with an imagesensor aligned with each other in a direction of an optical axis of thelens; and curing the resin to produce an engaging member of cured resin,wherein at least a part of the engaging member has a surface thatintersects with a direction of the optical axis of the lens, and on thesurface, the lens unit and the holding member are engaged with eachother.
 16. The camera module manufacturing method according to claim 15,further comprising a step of aligning the lens unit and the holdingmember with each other such that the optical axis of the lens and aperpendicular line passing through a center of a light receiving surfaceof the image sensor coincide with each other, and an image formingposition of the lens 21 coincides with the light receiving surface ofthe image sensor
 31. 17. The camera module manufacturing methodaccording to claim 15, wherein, in the step of producing the engagingmember, the resin is cured by light, and after that, the resin isfurther cured by heating.
 18. The camera module manufacturing methodaccording to claim 16, wherein, in the step of producing the engagingmember, the resin is cured by light, and after that, the resin isfurther cured by heating.
 19. The camera module according to claim 4,wherein the holding member has a notch that communicates an end of theholding member with the through hole.